In vehicle, when an engine oil runs short, or abnormality occurs in a charge system, a warning lamp on a meter panel, for example, an oil pressure warning lamp, or a charge warning lamp, etc. lights up or blinks. When the warning lamp lights up or blinks on the meter panel, a driver thinks “something to indicate is appeared. I am worried”, and the driver cannot concentrate on driving.
In Patent Document 1, when the warning lamp on the meter panel is turned on, a system in which a content explanation of the warning, or how to cope with the warning etc. is indicated on a display of a navigation device is described. However, in the above system, when the warning is generated during a route guidance by the navigation device, a description of the warning, or a description of how to cope with the warning is suddenly displayed on the display halfway along the route guidance. For this reason, the driver is disturbed by the lighting of the warning lamp on the meter panel, and a mental state of the driver may be further confused, since the display on the display of the navigation device suddenly changes. Finally, there is also a fear that it may interfere with driving and the like.